is this sentence a noun clause ?
i am sitting in the beach where the sun is shining.
if not how should i make it a noun clause using (where the sun is shining)
In that sentence "where the sun is shining" is telling where, so it's adverbial.
Try starting the sentence with that clause -- make it the subject of your sentence.
where the sun is shining is in NY
is this right?
Yes, that works. You could also say any of the following --
Where the sun is shining is where I want to be.
I want to be where the sun is shining.
He doesn't know where the sun is shining.
(and others)
No, the sentence "I am sitting on the beach where the sun is shining" does not contain a noun clause. It is a complex sentence that contains both an independent clause ("I am sitting on the beach") and a dependent clause ("where the sun is shining").
To use the phrase "where the sun is shining" as a noun clause, you could rephrase the sentence in the following way:
"The beach where the sun is shining is where I am sitting."
In this revised sentence, "The beach where the sun is shining" functions as a noun clause because it is the subject of the sentence.